What is Mild Cognitive Impairment?
Mild Cognitive Impairment (MCI) or more recently described as Mild Neurocognitive Disorder is a relatively new term that has become more widely understood over the past decade. An individual with MCI often reports subtle or mild memory difficulties and is often apparent to the individual with MCI and those that are close to them (i.e., spouses, family members, co-workers, etc.). As people get older, everyone becomes a little more forgetful, has a little more difficulty finding the right word, and gets distracted easier than in the past. However, research conducted over the past few decades has revealed that mild cognitive changes is not always normal, and in fact, may be the result of MCI. As such, a person experiencing MCI symptoms is neither normal nor demented and has subjective cognitive complaints and objective evidence of cognitive deficits.
Mild cognitive impairment has generally been subtyped into amnestic (having memory deficits) or nonamnestic (not having memory deficits) but involving single or multiple cognitive domains (i.e., language, reasoning, attention, etc.). For instance, a person can experience subtle-to-mild memory loss but still typically be able to care for themselves and function normally in every other aspect of their life. The person may also still be able to drive well, manage their finances and medications, and continue to live independently. As a result, the individual with MCI appears to function normally to those individuals around them which may lead to others underestimating the level of their memory deficits and simply attribute it to normal age related changes.
Amnestic – Occurs when memory loss is apparent both subjectively from the person and/or family member and objectively on formal neuropsychological testing. Generally, all other aspects of the person’s cognitive function (besides memory) are typically within normal limits.
Amnestic: Multiple-Domain- Occurs when there may be a slight to moderate memory impairment, but there will also be evidence of subtle-to-mild cognitive difficulties across other areas such as language, visual perceptual skills, attention, or reasoning/judgment.
Non-Amnestic: Multiple-Domain– The person may present with memory relatively spared but with evidence of subtle-to-mild cognitive difficulties across other areas such as attention, language, visual perceptual skills, or reasoning/judgment.
Non-Amnestic: Single Non-Memory Domain – This occurs when the person has a focal cognitive impairment in an area other than memory.
How does MCI differ from normal aging?
Neuropsychological tests are also frequently used to examine a person’s neurocognitive functioning (memory, attention, language, mood, reasoning, spatial skills, etc.) and can be very helpful in differentiating MCI from normal aging. Neuropsychological assessment offers significant advantages to all clinicians who evaluate and treat patients with cognitive complaints. These include establishing a quantitative cognitive baseline against which to measure future changes as well as determine what appears to be normal age-related cognitive changes. This evaluation provides an objective assessment of a wide range of cognitive domains and also can provide valuable information regarding mood and ability to carry out functional activities. A well-constructed neuropsychological test battery should be able to detect subtle cognitive deficits that could be missed even in patients considered to have a superior baseline intellectual ability.
Does MCI increase ones risk of developing dementia?
Some research has supported that a diagnosis of MCI can increase a persons risk of developing dementia. Researchers at Mayo Clinic found that MCI-Amnestic Subtype patients in their study progressed to Alzheimer’s disease at a rate of 12% per year. While MCI-Multiple Domain Subtype is thought to increase one’s risk of converting to Alzheimer’s disease and/or dementia related to cerebrovascular disease. MCI-Non-Amnestic Single Domain Subtype is believed to increase one’s risk of developing Vascular dementia, Dementia with Lewy bodies, and Frontotemporal dementia. However, not everyone who has MCI develops dementia. As of now, research continues to evaluate the direct association between MCI subtypes and a dementia diagnosis.